Smoke agent



. Patented Feb. 27, 1951 SMOKE AGENT Leo Finkelstein, Aberdeen, andSidney J Magram, Baltimore, Md., assignors to the United States ofAmerica as represented by the Secretary of War No Drawing. ApplicationNovember 8, 1943, Serial No. 509,506

(Granted under the act of March 3, 1883, as

3 Claims.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to us ofany royalty thereon.

This invention relates to a colored smokeforming composition.

The object of this invention is to provide an economical smoke-producingmixture which is particularly efficient when used in a smoke gremade orcandle but which may also be effectively utilized in artillery or mortarprojectives, and in smoke pots or various other pyrotechnical devices.

The smoke-forming composition of this invention comprises as principalingredients a mixture of a suitable dye, a fuel containing potassiumchlorate and sulfur, and a combustion-controlling agent, such as sodiumbicarbonate or potassium bicarbonate.

In the late war, small, portable, nonmissile devices which producedsmoke by progressive burning of a chemical filling were known as smokecandles. Devices of larger size, not so readily portable but producin amore enduring smoke cloud with longer burning by virtue of their size,were called smoke pots. More recently, the smoke candles were developedalong the lines of tear gas grenades and became known as smoke grenades.The grenades are a very convenient type of munition. They are easilycarried by troops, and they are readily set into action after projectionby small arms or when thrown by hand. However, the use of grenades forcolored smoke had the serious limitation that known smoke mixtures wereunsuitable in being too slow in igniting, too fast in burning, anderratic in burning.

The colored smoke-forming composition of the present invention does nothave the limitations of previously known mixtures and has proved to bean efiicient filling for utilization in the same kind of container as isused for tear gas grenades.

The composition has been satisfactorily standardized into one type withthe following variety of colors:

1. Yellow 4. Green 2. Orange 5. Blue 3. Red 6. Violet tain optimumproportions for forming a large amount of smoke.

Examples of satisfactory compositions are as follows:

amended April 30, 1928; 370 0. G. 757) 2 Example 1.-Yellow smoke mixture7 Percent Auramine 38 KClO3 -S 33.5 NaHCO3' 28.5

Example 2.-Ora.nge smoke mixture Percent Orange dye 45 KClO3S 31Mal-I003 24 The orange dye consists of a mixture of 39 parts of8-ch1oro-1-aminoanthraquinone and 6 parts of auramine.

Example 3.-Red smoke mixture Percent l-methy1aminoanthraquinone 40KClO3s 41 NaHCOa 19 Example 4.Green smoke mirture Percent Green dye 41KC103S 36 NaHCO; 23

The green dye consists of 29 parts of 1, l-di-p-- toluidinoanthraquinone and 12 parts of auramine.

Example 5.Blue smoke mixture Percent Indigo 64 KClO3-S 28' NaHCOa 8Example 6.Vz'o2et smoke mixture Percent Violet dye 44 KCIO3S 42 NaHCOs14v change in composition and on the burning time desired: Potassiumchlorate:

% minimum passes a No. U. S. Standard sieve 1 40% minimum passes a No.200 U. S. Standard sieve Sulfur:

99% minimum passes a No.

ard sieve 85% minimum passes a No.

ard sieve Sodium bicarbonate:

99% minimum passes a No.

ard sieve 50% minimum passes a No.

ard sieve Yellow dye:

70% minimum passes a No.

ard sieve 20% maximum passes a No.

ard sieve Orange dye:

92% minimum passes a No.

ard sieve 16% minimum passes a No.

ard sieve Red dye:

90% minimum passes a No.

ard sieve 70% minimum passes a No.

ard sieve Green dye:

95% minimum passes a No.

ard sieve 40% minimum passes a No.

ard sieve Blue dye:

90% minimum passes a No.

ard sieve 30% minimum passes a No. ard sieve Violet dye:

95 minimum passes a No.

ard sieve 60% minimum passes a No.

ard sieve Each of the smoke mixture charges'may be loaded into a renadebody and compressed therein under a high pressure, e. g., pressure of475 100 U. Stand- 200 U. Stand- 100 U. Stand- 200 U. Stand- 100 U.Stand- 200 U. Stand- 100 U. Stand- 200 U. Stand- 100 U. Stand- 200 U.Stand- 100 U. Stand- 200 U. Stand- 100 U. Stand- 200 U. Stand- 100 U. S.Stand- 200 U. S. Standpounds per square inch. On top the smoke charge 1in the grenade body may be placed a'starter charge formulated fromsilicon potassium nitrate and charcoal with a binder solution ofcellulose nitrate and acetone. The starter mixture may be contained in astarter cup and be ignited by an ordinary grenade fuse made up of aprimer and a train of black powder, the primer being set off bymechanical impact of a striker. The smoke mixture may be in any suitablecontainer without a starter cup and can be ignited directly simply by afuse.

' In the operation of a colored smoke grenade, heat evolved by thechemical reaction of the fuel ingredients volatilizes the'dye; and thedye vapors dispersed into the atmosphere condense to form a thickcolored smoke. The colored smoke, if formed in sufficient volume andlasting for sufficienttime, can be observed from long distances andserves as a signal, identification or for a variety of other purposes.

It is found to be extremely important to have the combustion reaction inthe smoke mixture The kinds of dyes found most suitable are commercialdyes as well as dyes specially made; it was found that someanthraquinone dyes, a diphenyl methane dye, an' indigo dye and othervat-type dyes could be used.

The use of the agent for controlling the combustion reaction is veryimportant. By moderating the temperature of the reaction withoutadversely affecting the ignition properties of the mixture, the agentmakes possible the selection of suitable organic dyes, lengthens thetime of burning and increases the smoke-developing eificiency of themixture. A characteristic of the combustion-controlling agent is theproperty of decomposing when heated to within the temperature range ofabout C. to 350 0., more preferably in the range of 200 C. to 300 C.Compounds having this characteristic are basic alkali bicarbonates, suchas sodium bicarbonate and potassium bicarbonate.

It is to be understood that the invention is not limited by the specificexamples and that various modifications are included within the scope ofthe invention.

We claim: 7

1. A colored smoke forming composition comprising a dry fuel mixture ofSulfur and potassium chlorate, a combustion controlling agent in aproportion of from about 8% to 28.5% C S and a dyestuff consisting byWeight of from not less than 35% nor more than 45% of said compositionselected from a group consisting of l methylaminoanthraquinone,l,4-diamino-2,3-dihydro anthraquinon and a mixture of each of saidquinones.

2. A colored smoke forming composition comprising a dry fuel mixture ofsulfur and potassium chlorate, a combustion controlling agent in lessthan 35% nor more than 45% of said com position selected from1,4-diamino-2,3-dihydro anthraquinone.

r LEO FINKELSTEIN.

SIDNEY J. MAGRAM.

REFEBENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Library).

La Nature for 1940, pages 240-244 (Les Nuages et Fumees Dans La GuerreModerne)

1. A COLORED SMOKE FORMING COMPOSITION COMPRISING A DRY FUEL MIXTURE OFSULFUR AND POTASSIUM CHLORATE, A COMBUSTION CONTROLLING AGENT IN APROPORTION OF FROM ABOUT 8% TO 28.5% NAHCO3 AND A DYESTUFF CONSISTING BYWEIGHT OF FROM NOT LESS THAN 35% NOR MORE THAN 45% OF SAID COMPOSITIONSELECTED FROM A GROUP CONSISTING OF 1 METHYLAMINOANTHRAQUINONE,1,4-DIAMINO-2,3-DIHYDRO ANTHRAQUINONE AND A MIXTURE OF EACH OF SAIDQUINONES.